With the continuous improvement of radio technology, a variety of radio services spring in large numbers. Whereas on one hand, there are limited radio-service-bearing spectral resources, which are in short supply with respect to increasingly higher requirements on bandwidths; and on the other hand, the utilization rate of the spectral resources is low under a conventional mode of fixed spectrum allocation.
Meanwhile, with the diversification of system requirements, the current situation is that various Radio Access Technologies (RATs) coexists; and service distribution differs depending on different RATs, different operators and different geographic areas.
Given the status quo and trend of network operation at the time, an operator would prefer a unified management of different systems coexisting over a short term or a geographic location, so as to adapt to a feature of a network traffic and optimize resource utilization. Typically, for example, the operator wants to add a next-generation network over an area or a period of time with an existing network, such as to add a Long Term Evolution (LTE) network on the basis of a deployed 2G/3G network. Furthermore, the operator wants to manage hardware resources and wireless resources of both the next-generation and the existing systems dynamically according to a change in cell traffic in a specific area. Adopted here is a new technology of Cognitive Radio (CR).
Given a cell configuration in a specific area, traffics of different services in a specific system or different systems may vary in an area over a daily cycle. In addition, in some specific areas, some cells may be jammed (i.e., with a high probability of call blockage) and surrounded by a plurality of cells with low probabilities of call blockage. In addition, in the case that two or more RATs are deployed in the same area, traffics of different services of an RAT may distribute differently over time relative to another RAT. For example, if a Global System for Mobile communication (GSM) and an LTE system are deployed simultaneously in an area; in a period of time, the GSM may be under-loaded due to fewer GSM users and lighter service traffic, while a network side of the LTE system may be overloaded due to user assembling, heavy service traffic and strained resource supply in the LTE system. In such a scenario, it is a waste for the GSM to include idle resources while the LTE system is in short supply of resources. Therefore, a problem yet to be addressed is how to coordinate the utilization of spectral resources in a primary system and between RATS.